GFCI on multi branch circuit

[mach158]

Hope I used the correct term in the subject line.

Anyway, I ran 12/3 around the perimeter of my shop for outlets. I want to use both circuits of the 12/3 and it is my understanding I can pull this off without a gfci breaker by doing the following.

First I need a 20 amp double pole breaker then I hook up a gfci outlet on the black wire then hook up a gfci outlet on the red line then i can switch to regular outlets as long as they are in series. Am I understanding this correctly?

I seen something mentioned about pigtailing the neutrals but dont understand if thats at the gfci plug or the plugs down stream of the gfci.

If I pigtail the nuetral on the gfci and not wire theough it then wouldnt that defeat the purpose of the gfci?

Sent from my SM-G900R4 using Tapatalk

 

[Mustang51js]

Since you ran 12/3 all the way around you would need a gfi outlet at each box. What you were supposed to do is run a 12/3 to first box,then 12/2 out for each circuit and that 12/2 would be on the load side,and the neutral at the first box with the 12/3 in it would have to be wire nutted together with a tail. Since you ran 12/3 all around you can try and find a 2 pole gfi breaker or install a gfci in each box,otherwise you would have to make it one circuit for everything. If you put gfi in each then you can wirenut each wire with a tail to line side of gfi.

 

[dfiler2]

You can use a double pole GFCI breaker, a little more money but it works fine. Ask me how I know.

http://www.amazon.com/gp/product/B00DW472XE/?tag=atomicindus08-20

With the GFCI breaker you cant and don't need to use the GFCI outlets.

 

[mach158]

Thanks.

I just ordered two GFCI double poles since it will end up being cheaper.

 

[wyliesdiesels]

Did u already close up the walls?

 

[mach158]

Nope. Have no plans to close up the walls anytime soon.

Sent from my SM-G900R4 using Tapatalk

 

[LXCam]

You can't use a double pole unless these are all 240 volt circuits. I assuming you're installed 120v receptacles right? If so you needed a dedicated neutral back to the breaker for each circuit. GFI's work like a deductive calculator. The out going (hot lead) and return (neutral) currents must match almost exactly, matter of fact just within a few miliamps or it will trip. There is no sensing circuit for the ground so if the two currents do not match this is how it knows there is a ground fault.

 

[mach158]

You can't use a double pole unless these are all 240 volt circuits. I assuming you're installed 120v receptacles right? If so you needed a dedicated neutral back to the breaker for each circuit. GFI's work like a deductive calculator. The out going (hot lead) and return (neutral) currents must match almost exactly, matter of fact just a few miliamps or it will trip. There is no sensing circuit for the ground so if the two currents do not match this is how it knows there is a ground fault.

It is my understanding now that any shared neutral requires a double pole and one outlet will be black wire and one outlet will be red wire and it will alternate like that. So by then pigtailing the neutral at every outlet it will work correctly off a gfci breaker.

Did I misunderstand something? Im still learning.

Sent from my SM-G900R4 using Tapatalk

 

[Jlarson]

You can't use a double pole unless these are all 240 volt circuits. I assuming you're installed 120v receptacles right? If so you needed a dedicated neutral back to the breaker for each circuit.

No he doesn't, 2 pole GFCI's work on MWBC's just fine.

 

[wyliesdiesels]

You can't use a double pole unless these are all 240 volt circuits. I assuming you're installed 120v receptacles right? If so you needed a dedicated neutral back to the breaker for each circuit. GFI's work like a deductive calculator. The out going (hot lead) and return (neutral) currents must match almost exactly, matter of fact just within a few miliamps or it will trip. There is no sensing circuit for the ground so if the two currents do not match this is how it knows there is a ground fault.

Wrong.

A double pole GFCI will work fine for this application.

How do u think the 120v loads in a 240v hot tub function without the 240v double pole GFCI breaker tripping?